Rin Otomo operates drones for the 15th Joint Task Force of Japan's National Defense Forces. She trained at the same military academy and served alongside Teppei Sugo. Her role involves coordinating aerial support for ground units. She marries fellow soldier Itsuki Otomo, forging a close bond in both their military duties and personal lives. During service, she conceives their child. Citing concerns over her Psycho-Pass hue clouding, she leaves active duty, though the pregnancy motivates her departure. She transitions to a Military System Engineer role at Nago Base while awaiting the child's birth. Following Itsuki's disappearance during the overseas Operation Foot Stamp, Rin experiences profound distress. Military superiors inform her Itsuki is missing in action, withholding specific details. This triggers severe mental deterioration, culminating in a miscarriage. The dual loss of husband and unborn child darkens her Psycho-Pass hue significantly. Her demeanor shifts from gentle and calm to apathetic and withdrawn. After leaving the military entirely, she gains employment at a television station. While outwardly accepting Itsuki's death, she privately investigates Operation Foot Stamp. Her research uncovers evidence that military command deliberately sacrificed Itsuki's unit to test a banned nano-based VX nerve agent bioweapon, subsequently concealing this fact. This revelation fuels a desire for vengeance against those responsible for her husband's death. To execute her plan, she infiltrates Nago Base using security credentials obtained by hacking Teppei Sugo's military account. She repurposes two combat training robots, originally belonging to Itsuki, injecting them with attack protocols. Through one robot, she confronts Sugo directly, revealing the truth about Operation Foot Stamp and the military's betrayal. Her objective focuses on assassinating high-ranking officers, including Admiral Monto Minatoya and Colonel Yoshito Takaesu, whom she holds accountable. During an attempt to kill Colonel Takaesu, she falls victim to a deception. A holographic projection of Takaesu distracts her, enabling a concealed drone to shoot her from behind. This action results in her death before she achieves her vengeance. Her exposure of the conspiracy contributes to the eventual identification and termination of the responsible commanders by Public Safety Bureau personnel, as their direct involvement in her murder elevated their Crime Coefficients. Her surname Otomo combines the characters for "big, great" (大) and "friend, companion" (友), while her given name Rin (燐) translates to "phosphorus."